Retirement Plans - Schedule of Net Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Interest cost	$ 206	$ 251
Net amortization	97	72
Net periodic pension cost	$ 303	$ 323

Amount of cost recognized for passage of time related to defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Name:	us-gaap_DefinedBenefitPlanInterestCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration